Electrode holder for gas-arc gauging torch

ABSTRACT

A holder for an electric arc gouging electrode, in which an auxiliary gas supply is delivered to the holder and jetted from a nozzle at its forward end in a single stream offset but adjacent to and directionally parallel with the electrode. The auxiliary gas supply is normally air, and is used to eject the molten metal pool formed at the arc. The direction of offset of the gas jet is controllable by rotation of the forward portion of the nozzle. A safety valve within the holder interrupts the air supply in the event of accidental disengagement of the electrode from its clamping member, to prevent air-projection of the electrode in missile-fashion.

United States Patent Maddison [451 Mar. 21, 1972 [s41 ELECTRODE HOLDER FOR GAS-ARC GING TORCH [72] inventor: John Henry Maddison, 509 Latimer Street, Nelson, British Columbia, Canada [22] Filed: Apr.6,1970

211 Appl.No.: 25,856

52 us. Cl. ..219/70, 219/69 D, 219/144 51 rm. CI. ..'.a2 ak9/2s, B23p-1/08 [581 Field of Search ..2l9/69 E,69 F, 70, 142-144,

[5 6] References Cited UNITED STATES PATENTS 2,475,594 7/1949 Danhier ..2l9/70 2,727,127 12/1955 Dority ..2l9/70 Primary Examiner-R. F. Staubly Attorney-John E. Prothroe [57] ABSTRACT A holder for an electric arc gouging electrode, in which an auxiliary gas supply is delivered to the holder and jetted from a nozzle at its forward end in a single stream offset but adjacent to and directionally parallel with the electrode. The auxiliary gas supply is normally air, and is used to eject the molten metal pool formed at the arc. The direction of offset of the gas jet is controllable by rotation of the forward portion of the nozzle. A safety valve within the holder interrupts the air supply in the event of accidental disengagement of the electrode from its clamping member, to prevent air-projection of the electrode in missile-fashion.

I 2 Claims, 2 Drawing Figures ELECTRODE HOLDER FOR GAS-ARC GAUGING TORCH The present invention relates generally to electrode holders for electric cutting and gouging torches, and more particularly to improved electrode holders embodying a gas jet nozzle in direct association with an electrode clamp element, whereby the gas jet is directed substantially parallel to the electrode, but offset to the electrode, thereby jetting the molten metal formed at the tip of the electrode, out of the cut.

An object of the present invention is to provide an electrode holder for electric cutting and gouging torches, in which a gas jet is directed substantially parallel to, and offset from the longitudinal axis of the electrode, so that the molten metal formed by the arc is continuously swept from the cut.

Another object of this invention is to provide an electrode holder in accordance with the preceding object,.in which the direction of offset of the gas jet may be selected by the operator, in order to control the discharge of the molten metal from the cut.

A further object of the present invention is to provide an electrode holder for gouging torches, in which a safety valve is incorporated, which automatically shuts off the gas supply in the event the electrode becomes accidentally released from the holder, while the tool is under gas pressure, thereby minimizing the likelihood of the electrode being discharged from the electrode holder in a dangerous fashion. 7

A still further object of the present invention is to provide an electrode holder for gouging torches, embodying a gas jet nozzle in direct association with the electrode clamp element, in which a single gas jet is utilized, directed parallel to the longitudinal axis of the electrode, effective as a directional jet over the full length of the electrode, thereby eliminating the requirement for frequent adjustment of the electrode, as it becomes consumed in the cutting and gouging operation.

Still another object of the present invention is to provide an electrode holder for gouging torches which is simple in construction, easy to use, dependable and long lasting, and relatively inexpensive to manufacture.

These, together with other objects and advantages which will become subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a longitudinal section of the electrode holder, depicting the electrode in place;

FIG. 2 is an enlarged perspective view of the safety valve of the electrode holder.

Referring specifically to the drawings, the electrode holder 10 of this invention, in its basic construction, includes outer front and rear insulating members 11 and 12, constructed of suitable electrically insulating material, such as neoprene rubber, and electrically conductive body members 13 and 22, positioned within the exterior front and rear insulating members 11 and 12.

Referring specifically to FIG. 1, a cylindrical electrode head member 13, is formed with a lengthwise centrally axial bore 14 at its forward end 15, which leads into a valve chamber 16 formed at its rearward end 17, so that the bore 14 communicates with the valve chamber 16 to admit the passage of gas from the valve chamber 16 into the bore 14, as will be hereinafter explained.

The valve chamber 16 includes a chamfered forward portion 18, which provides a base for a neopreneO-ring valve seat 19, depicted in'cross section on FIG. 1.

The rearward end of the electrode head member 13 carries threads 20, which engage with cooperating threads on the forward end 21 of a base member 22, constructed like the electrode head member 13 of suitable metal, such as mild steel or aluminum. The base member 22 is generally cylindrical, and includes a longitudinal bore 23, drilled axially therethrough, so that it communicates at its forward end with the valve chamber 16, and at its rearward end with a gas hose fitting 24, and a gas hose 25.

Operating within the valve chamber 16 is a valve 26, desirable constructed of aluminum alloy, having a curved face 27, which registers with the O-ring valve seatl9, when the valve 26 is in closed position.

The valve 26 is formed with a guide ring 28, of a diameter such that the valve 26 will freely slide lengthwise within the valve chamber 16, as will be hereinafter explained.

The rearward end of the valve 26 is formed with a flat face 29, which engages with the stop-portion 30 of the forward end of the base member 22, when the valve is in fully open position.

A recess, such as the bottomed bore 31, is formed in the forward end of the valve 26, of a diameter sufiicient to freely accommodate an electrode rod 32.

Lengthwise ports 42 formed exteriorly on the valve 26 at its rearward end as depicted in FIG. 2 permit the forward flow of gas from the bore 23 of the bore member 22, into the valve chamber 16. Additional ports 43, FIG. 2, formed exteriorly on the guide ring 28 of the valve 26, permit the forward flow of gas from the valve chamber l6 past the valve 26 into the forward end of the chamber 16 and thus into the bore 14 formed in the electrode head member 13.

An insulated connector bar 33, having a threaded end portion 34, engages with a threaded hole in the side of the base member 22, and provides means of supplying electrical energy to the electrode holder 10, by means of a conventional electrical conduit fitting (not illustrated) secured to its uninsulated exposed contact end 35.

A clamping screw 36, including a threaded portion 37 and an electrically insulating head 38, is positioned at the forward end of the electrode holder 10, as depicted in FIG. 1, and engages with a threaded hole 39 in the electrode head member 13, drilled radially to communicate with the bore 14 therein.

The diameter of the bore 14 is substantially in excess of the diameter of the electrode 32, so that when the electrode 32 is inserted into the electrode holder 10, and secured in position with the clamping screw 36, a longitudinal opening, crescentshaped in cross section, remains between the adjacent face of the electrode 32 and the wall of the bore 14, thereby forming a gas discharge nozzle, to permit the discharge of gas lengthwise along the adjacent extended portion of the electrode 32.

The front insulating member 11 is formed with an internal diameter to closely engage the forward portion 15 of the electrode head member 13 in a press fit. Similarly, the rear insulating member 12 engages the rearward portion 17 of the electrode head member 13 in a press fit. A connector ring 40, similarly formed of electrically insulating material such as neoprene, overlaps the adjacent ends of the front insulating member 11 and the rear insulating member 12, in a loose fit. The internal, diameter of the rearward portions 41 of the rear insulating member 12 is a loose fit with the coupling 24.

In operation, a gouging rod, normally of powdered carbon, copper-coated over its full length and well known to the art to which this invention relates, will be inserted into the forward end of the oversize bore 14, until it engages with the recess 31 in the valve 26, and will be pressed home until the rearward face 29 of the valve 26 comes into engagement with the stop surface 30 on the base member 22. Thus, the valve 26 is lifted so that its face 27 is remote from the O-ring seat 19. The elec-.

trode 32 will then be secured in place by the clamping screw 36.

Gas, such as air, is admitted from the hose 25 into the base member 22, where it flows forwardly through the bore 23 and into the valve chamber 16 by means of the communicating ports 42.

Under pressure, the gas will flow forward through the ports 43 formed in the guide ring 28 of the valve, and into the crescent-shaped nozzle 43, formed by the adjacent surfaces of the electrode 32 and the bore 14. The gas will discharge at high velocity under pressure from the forward endof the'nozzle, and with some limited dispersion will follow the length of the electrode 32 to the are formed at the work, and will impinge on the pool of molten metal formed at the arc, jetting the molten metal from the area of the arc in the direction of the opposite side of the electrode.

The operator may control the position of the jet, and thereby the direction of discharge of the molten metal spray, by simply rotating the forward insulating member 1 1, and the electrode head member 13 in press fit therewith, about the base member 22 by means of the loose threads 20, which operate to hold the electrode head member 13 and the base member 22 together in operative relationship, while at the same time permitting their relative rotation about their longitudinal axes.

Because the gas jet formed in the crescent-shaped noule 43 flows parallel to the longitudinal axis of the electrode rod 32, as the rod 32 is consumed from its tip in the gouging operation, no adjustment of the electrode rod 32 within the electrode holder is required in order to maintain continual impingement of the gas jet thus formed upon the arc.

Should the electrode rod 32 become accidentally disengaged from the screw clamp 36, pressure of the gas within the valve chamber 16 will force the valve 26 forwardly into seating engagement against the O-ring valve seat 19, thereby cutting off the supply of gas to the bore 14, thus preventing the electrode 32 from being ejected out of the electrode holder 10 as a potentially dangerous projectile. When reloaded with an electrode, the valve 26 is positioned again as described above, thereby reestablishing the forward discharge of gas from the nozzle.

The selection of the gas used with the device of this invention will depend on the characteristics of the operation; oxidation of the molten metal is effected when the gas used is air or oxygen, and oxidation is retarded by gas blanketing of the arc and molten metal if the gas is inert or reducing.

The electrode holder of the present invention is inexpensive to produce, durable in operation, light in weight, convenient to employ, and permits the operator to have fingertip control of the continuous jet, in order to control the direction of the discharge spray of molten metal at the arc.

Since various modifications can be made to the invention herein described within the scope of the inventive concepts disclosed, it is not intended that protection of the said invention should be interpreted as restricted to the modification or modifications or known parts of such concept as have been particularly described, defined, or exemplified, since this disclosure is intended to explain the construction and operations of such concept, and not for the purpose of limiting protection to any specific embodiment or details thereof.

What I claim as my invention is:

1. An electrode holder for gas-arc gouging torch, comprising in combination, a handle including an exterior electrically insulating cover portion and an electrically conductive body portion substantially enclosed within said exterior electrically insulating cover portion, said body portion including a generally cylindrical head member and a generally cylindrical electrode base member to which said electrode head member is electrically connected and pivotally secured inaxially concentric end-abutting relationship, said electrode head member defining therewithin a concentrically located longitudinally extending cylindrical bore having a cross-sectional area substantially greater than the cross-sectional area of the electrode rod, gas conduit means operatively connected to said cylindrical bore and adapted to deliver gas under pressure to said cylindrical bore, electrode clamping means on said body portion of said handle operable to secure said electrode in nonconcentric axial contact with the interior wall of said cylindrical bore so as to define a gas nozzle between said electrode and that portion of said interior wall of said cylindrical bore remote from said axial contact with said electrode, electrical conductor means connected to said body portion of said han dle and adapted to deliver electrical energy to said electrode, and safety valve means whereby gas delivered under pressure to said nozzle is interrupted upon disengagement of said electrode from said electrode clamping means, said safety valve means comgrising a valve chamber within said electrode base member an communicating at its forward end with said cylindrical bore and at its rearward end with said gas conduit means, an annular valve seat at the forward end of said valve chamber, and a valve operatively positioned within said valve chamber and adapted to lift from said valve seat when the electrode rod is inserted into said bore and the rearward end thereof comes into operative engagement with said valve, and to interrupt said gas flow from said valve chamber to said cylindrical bore when said electrode rod is disengaged from said valve.

2. In an electrode holder for a gas-arc gouging torch, the combination of an elongated electrically conductive body having front and rear endsand provided with an axial bore and with an enlarged valve chamber intermediate the ends of said bore, the front end portion of said bore being adapted to receive an electrode of a smaller diameter than the bore so as to provide a gas passage alongside of the electrode, means for clamping an electrode in the front end portion of the bore, means for delivering gas under pressure into the rear end portion of the bore and into said valve chamber, a valve seat provided at the junction of said chamber with the front end portion of the bore, and a valve member slidable forwardly and rearwardly in said chamber into and out of engagement with said valve seat, said valve member being slid rearwardly by insertion of an electrode into the front end portion of the bore and being slid forwardly by gas pressure in the rear end portion of the bore when said clamping means becomes loosened. 

1. An electrode holder for gas-arc gouging torch, comprising in combination, a handle including an exterior electrically insulating cover portion and an electrically conductive body portion substantially enclosed within said exterior electrically insulating cover portion, said body portion including a generally cylindrical head member and a generally cylindrical electrode base member to which said electrode head member is electrically connected and pivotally secured in axially concentric endabutting relationship, said electrode head member defining therewithin a concentrically located longitudinally extending cylindrical bore having a cross-sectional area substantially greater than the cross-sectional area of the electrode rod, gas conduit means operatively connected to said cylindrical bore and adapted to deliver gas under pressure to said cylindrical bore, electrode clamping means on said body portion of said handle operable to secure said electrode in nonconcentric axial contact with the interior wall of said cylindrical bore so as to define a gas nozzle between said electrode and that portion of said interior wall of said cylindrical bore remote from said axial contact with said electrode, electrical conductor means connected to said body portion of said handle and adapted to deliver electrical energy to said electrode, and safety valve means whereby gas delivered under pressure to said nozzle is interrupted upon disengagement of said electrode from said electrode clamping means, said safety valve means comprising a valve chamber within said electrode base member and communicating at its forward end with said cylindrical bore and at its rearward end with said gas conduit means, an annular valve seat at the forward end of said valve chamber, and a valve operatively positioned within said valve chamber and adapted to lift from said valve seat when the electrode rod is inserted into said bore and the rearward end thereof comes into operative engagement with said valve, and to interrupt said gas flow from said valve chamber to said cylindrical bore when said electrode rod is disengaged from said valve.
 2. In an electrode holder for a gas-arc gouging torch, the combination of an elongated electrically conductive body having front and rear ends and provided with an axial bore and with an enlarged valve chamber intermediate the ends of said bore, the front end portion of said bore being adapted to receive an electrode of a smaller diameter than the bore so as to provide a gas passage alongside of the electrode, means for clamping an electrode in the front end portion of the bore, means for delivering gas under pressure into the rear end portion of the bore and into said valve chamber, a valve seat provided at the junction of said chamber with the front end portion of the bore, and a valve member slidable forwardly and rearwardly in said chamber into and out of engagement with said valve seat, said valve member being slid rearwardly by insertion of an electrode into the front end portion of the bore and being slid forwardly by gas pressure in the rear end portion of the bore when said clamping means becomes loosened. 